U.S. patent application number 11/850407 was filed with the patent office on 2008-03-06 for method for affecting biomechanical properties of biological tissue.
This patent application is currently assigned to Ace Vision USA. Invention is credited to Lucinda Camras, AnnMarie Hipsley.
Application Number | 20080058779 11/850407 |
Document ID | / |
Family ID | 39152824 |
Filed Date | 2008-03-06 |
United States Patent
Application |
20080058779 |
Kind Code |
A1 |
Hipsley; AnnMarie ; et
al. |
March 6, 2008 |
Method for Affecting Biomechanical Properties of Biological
Tissue
Abstract
A method for changing at least one biological property of a
biological tissue, the method having the steps of providing a
biological tissue having at least a first layer; evaluating the
topography, biomechanical and fundamental properties of the
biological tissue by layer; and orienting a matrix complex in the
biological tissue, wherein the matrix complex has matrices that are
balanced in a mathematical relationship, wherein each of the
matrices comprises a perforation formation in the tissue, and
wherein the mathematical relationship comprises a mathematical
algorithm.
Inventors: |
Hipsley; AnnMarie; (Silver
Lake, OH) ; Camras; Lucinda; (Omaha, NE) |
Correspondence
Address: |
Daniel J. Schule
Suite 500
388 S. Main Street
Akron
OH
44311
US
|
Assignee: |
Ace Vision USA
Silver lake
OH
|
Family ID: |
39152824 |
Appl. No.: |
11/850407 |
Filed: |
September 5, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60842270 |
Sep 5, 2006 |
|
|
|
Current U.S.
Class: |
606/4 ; 606/14;
607/89 |
Current CPC
Class: |
A61F 2009/00891
20130101; A61F 2009/00872 20130101; A61F 2009/00865 20130101; A61F
2009/00857 20130101; A61F 9/008 20130101 |
Class at
Publication: |
606/004 ;
606/014; 607/089 |
International
Class: |
A61F 9/008 20060101
A61F009/008; A61B 18/20 20060101 A61B018/20 |
Claims
1. A method for changing at least one biological property of a
biological tissue, the method comprising the steps of: providing a
biological tissue having at least a first layer; evaluating the
topography, biomechanical and fundamental properties of the
biological tissue by layer; and orienting a matrix complex in the
biological tissue, wherein the matrix complex has matrices that are
balanced in a mathematical relationship, wherein each of the
matrices comprises a perforation formation in the tissue, and
wherein the mathematical relationship comprises a mathematical
algorithm.
2. The method of claim 1, wherein the at least one biological
property is elasticity, shock absorption, resilience, mechanical
dampening, pliability, stiffness, rigidity, configuration,
alignment, deformation, mobility, or tissue volume.
3. The method of claim 1, wherein the biological tissue has a range
of isotropic elastic constants across the medium; and wherein the
matrices have a position within the matrix complex, wherein the
position of the matrices is selected to create a non-monotonic
force deformation relationship in the biological tissue.
4. The method of claim 1, wherein each matrix has a row length and
a column length, wherein there is a linear algebraic relationship
between the row length and the column length; and wherein each
perforation in the matrix formation has continuous linear vector
spaces with derivatives up to infinite number relationship "n".
5. The method of claim 4, wherein each matrix has a surface area
and wherein the sum of the surface areas of the matrices is the
matrix complex surface area; and wherein each perforation has a
proportional relationship within the matrix and matrix complex
surface area.
6. The method of claim 1, wherein the matrix complex is positioned
with respect to the biological tissue to achieve within the
biological tissue a substantial equilibrium of forces in both
static and dynamic conditions.
7. The method of claim 6, wherein the matrix complex is positioned
with respect to the biological tissue to reduce shearing effect
between the matrices within the matrix complex and between the
perforations within the matrix to increase the integrity of the
tissue.
8. The method of claim 1, wherein each perforation has a linear
relationship with the other perforations within each matrix and the
complex of matrices individually.
9. The method of claim 1, wherein the perforation is formed by
excising a volume of the biological tissue.
10. The method of claim 9, wherein the shape of the excised volume
is substantially cylindrical.
11. The method of claim 9, wherein each perforation defines a point
within each matrix and matrix complex on the surface of the
biological tissue.
12. The method of claim 1, wherein the matrices are
tessellated.
13. The method of claim 12, wherein the tessellation comprises a
repeating pattern and tessellations are Euclidian, non-Euclidean,
regular, semi-regular, hyperbolic, parabolic, spherical, or
elliptical and any variation therein.
14. The method of claim 13, wherein the tessellation comprises a
non-repeating pattern and tessellations are Euclidian,
non-Euclidean, regular, semi-regular, hyperbolic, parabolic,
spherical, or elliptical and any variation therein.
15. The method of claim 13, wherein the tessellation is directly
related to one or more of stress or shear strain atomic
relationships within the biological tissue and between the
biological tissue and its surrounding tissues by a mathematical
array of position vectors between perforations.
16. The method of claim 15, further comprising the step of
computing the mathematical array of position vectors between
perforations.
17. The method of claim 13, wherein the tessellation is indirectly
related to one or more of stress and shear strain atomic
relationships between tissues.
18. The method of claim 15, wherein the mathematical algorithm
comprises an atomic relationship factor, wherein the atomic
relationship factor comprises a predictable relationship between
the volume removed in each perforation and the change in the
biological property of the biological tissue.
19. The method of claim 18, wherein the relationship of the removed
volume to the magnitude of biomechanical change in the tissue is
mutually exclusive.
20. The method of claim 12, wherein the tessellation is a square
having the property of being able to be subdivided into a
tessellation of equiangular polygons to a derivative of n.
21. The method of claim 20, wherein the tessellation comprises all
infinite number of tessellating tetrahedrons within the square for
desired tissue effect and volumetric requirement.
22. The method of claim 20, wherein the tessellation comprises a
finite number of tessellating tetrahedrons within the square for
desired tissue effect and volumetric requirement.
23. The method of claim 1, wherein the mathematical algorithm uses
a factor of .PHI. or Phi to find the most efficient biological
mapping for the proportionate placement of the matrices to alter
the biological property of said biological tissue.
24. The method of claim 23, wherein the factor is selected from the
group consisting of an addition of; a subtraction of, a
multiplication of, a division of, an exponent of, and a root of,
Phi
25. The method of claim 23, wherein the factor of .PHI. or Phi is
1.62 and represents any fraction of a set of spanning vectors in a
lattice having the shortest length relative to all other vectors'
length.
26. The method of claim 23, wherein the mathematical algorithm
includes a non linear hyperbolic relationship between planes of
biological tissue and at any boundary or partition of neighboring
tissues, planes and spaces in and outside of the matrices.
27. The method of claim 23, further comprising the step of
providing a software program adapted to calculate the location of
the matrix complex on the biological tissue and the location of the
perforations within the matrices, all using the mathematical
algorithm, related to the structural hierarchy of the biological
tissue.
28. The method of claim 27, wherein the structural hierarchy is
determined by understanding homogeneity of layers of biological
tissue.
29. The method of claim 27, wherein the software program transmits
the location of the matrix complex and the perforations to a tissue
perforating device.
30. The method of claim 29, wherein the software program further
transmits control instructions to the tissue perforating
device.
31. The method of claim 29 wherein the tissue perforating device
has laser or scanning device that contains a biofeedback mechanism
either within the head of the laser or within the device.
32. The method of claim 30, wherein the tissue perforating device
is a laser.
33. The method of claim 1, wherein the biological tissue is
sclera.
34. The method of claim 1 wherein the biological tissue is any
arterial lumen or nervous tissue lumen or sheath.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Patent Application
Ser. No. 60/842,270, entitled METHOD FOR AFFECTING BIOMECHANICAL
PROPERTIES OF BIOLOGICAL TISSUE, filed Sep. 5, 2006. Furthermore,
this application hereby incorporates by reference all of the
subject matter of U.S. Patent Applicant's Ser. No. 60/842,270.
BACKGROUND
[0002] Corrective eye procedures are well-known, and the art has
now advanced to the stage at which self-contained laser based
systems are sold as stand alone units to be installed in a
surgeon's operatory or a hospital, as desired. Thus,
hospitalization is not necessarily required in order to perform
such ophthalmological surgery.
[0003] Such systems typically include a p.c. (personal computer)
type work station, having the usual elements (i.e., keyboard, video
display terminal and microprocessor based computer with floppy and
hard disk drives and internal memory), and a dedicated
microprocessor based computer which interfaces with the p.c. work
station and appropriate optical power sensors, motor drivers and
control elements of the ultraviolet laser, whose output is
delivered through an optical system to the eye of the patient.
[0004] In use, after the patient has been accommodated on a surgery
table or chair, the system is controlled by the operator (either
the surgeon or the surgeon and an assistant) in order to prepare
the system for the delivery of the radiation to the patient's eye
at the appropriate power level and spatial location on the corneal
surface.
[0005] In some systems, a provision is made for permanently
recording on a plastic card made of PMMA (polymethylmethacrylate) a
spot image of the laser beam used in the surgical operation. This
spot is recorded prior to the operation to ensure that the beam
power is properly adjusted and to provide a permanent record of the
beam used. PMMA is typically used due to the characteristic of this
material of having a closely similar ablative photodecomposition
response to that of the human corneal tissue. After the surgery has
been performed, the resultant data is typically made part of a
permanent record, which becomes part of the patient's file.
[0006] The utility of such ophthalmological surgery is well-known,
and there is therefore a need for new methods directed to improving
ophthalmological surgery even further.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] In the accompanying drawings, which are incorporated in and
constitute a part of the specification, embodiments of the
invention are illustrated, winch, together with a general
description of the invention given above, and the detailed
description given below, serve to exemplify embodiments of the
invention:
[0008] FIG. 1 is a cross-sectional view of the human eye and the
optics relating to it.
[0009] FIG. 2 is a cross-sectional view of the human eye and the
optics relating to it.
[0010] FIG. 3 is a cross-sectional view of the human eye and
general biomechanics during accommodation.
[0011] FIG. 4 is in exploded view of the human eye and the
biomechanical strain on sclera.
[0012] FIG. 5 is a cross-sectional view of the human eye and
general biomechanics during accommodation.
[0013] FIG. 6a is a cross-sectional view of biological tissue
having perforations therein.
[0014] FIG. 6b is a perspective view of biological tissue having
nine perforations therein.
[0015] FIG. 7 is a perspective view of the energy storage, shock
absorption, and elasticity restoration of perforated biological
tissue.
DETAILED DESCRIPTION
[0016] Embodiments are directed to a method for changing a least
one biological property of a biological tissue, by means of
orienting in the biological tissue a matrix complex (which may be
referred to as a biomatrix), which is a complex of at least one,
matrix arranged in an orientation with respect to other matrices in
the complex. The orientation of the matrices in the matrix complex
is governed by a mathematical relationship that comprises a
mathematical algorithm. It is desirable to achieve a change in at
least one biological property without substantially undermining the
structural integrity of the biological tissue. Indeed, it is within
the scope of the present invention to actually improve the overall
structural integrity and/or operational functionality of the
biological tissue by means of introducing the matrix complex
(described below) into the biological tissue. Exemplary of the
present invention, the method may be practiced for the purpose of
achieving decompression or soft tissue release of load bearing or
constricted (or contracted) connective tissues.
[0017] For purposes of this invention, a matrix comprises a
plurality of perforations (at least two, and preferably three or
more) of the biological tissue, wherein the perforations are
arranged in a pattern or mathematical orientation with respect to
each other, to form the matrix. The perforations form lattice
points or partitions within the biological tissue in the area of
the matrix.
[0018] A perforation is the result of the selective removal or
manipulation of tissue, by excision, incising, vaporization, and
ablation. The perforation will preferably extend from the surface
of the biological tissue into the biological tissue. The
perforation(s) may extend entirely through the biological tissue or
only partially through the biological tissue. The perforation may
extend through one or more sub-tissues (described below). The
perforation may have the form of a pore, having a first end
adjacent the surface of the tissue and second end, which may be at
a depth x into the tissue wall, and a pore wall extending from the
first end to the second end. The perforation may be substantially
cylindrical; however, any shape may be selected with sound
judgment. The formation of a perforation will result in the removal
of a volume of tissue, which volume may be calculated with respect
to the physical dimensions of the pore itself, including cross
sectional area and depth. According to one aspect of the invention,
the volume of tissue removed in each perforation and/or the total
volume of tissue removed in the sum of all perforations in the
matrix complex may bear a proportional mathematical relationship to
the biological property being affected, such that it will be
possible to limit or control the change in the biological property
by limiting or controlling the volume of tissue removed in the
matrix complex.
[0019] The perforation may be formed by cutting, incinerating, or
vaporizing the tissue by mechanical, light, chemical or atomic
force means. Other suitable means of forming the perforation may
also be selected. In a preferred embodiment, the perforation may be
formed by means of a laser. Laser vaporization of target soft
tissue has very little effect on surrounding soft tissue structures
or tissues.
[0020] Laser features may include: [0021] i. Er:Yag specifications
in the 2.94 um range [0022] ii. any laser in the full range of the
light spectrum [0023] iii. nano or biofilms applications to create
porous surfaces [0024] iv. chemical or biochemical applications
[0025] v. fiberoptic system OR colluminated arm system to deliver
2.94 um wavelength [0026] vi. custom tips [0027] vii. Free electron
Laser or FEL Er:Yag system [0028] viii. Handpiece can be attached
or remote [0029] ix. Handpiece may or may not include a probe.
(Shen) with or without a feedback mechanism, with or without laser
controls incorporated into the handpiece [0030] x. Nanotechnology
application for scanning, feedback & delivery of predetermined
specifications of tissue removal [0031] xi. 3D images & nano
images assisted visualization of soft tissue may or may not be used
[0032] xii. Tips can be quartz, sapphire, or other in contact or
non contact
[0033] The method of the present invention comprises the step of
providing a biological tissue. Suitable biological tissues may
include muscle tissue, connective tissue, fascia, scar tissue,
skill, cartilage and bone. The present disclosure does not intend
to limit the type of biological tissue for which the methods may be
applied. Though the invention contemplates the use of biological
tissue, it is recognized that the methods may be practiced in whole
or in part on non-biological tissues for the purposes of achieving
an effect on the physical and structural properties of the
non-biological tissues. In the preferred embodiment, the biological
tissue is the sclera or other soft or connective tissues of the
eye.
[0034] It will be understood by one of ordinary skill in the art
that a biological tissue will have certain physical/mechanical and
biological properties, which influence the operation of the
biological tissue internally (i.e., within itself) and within its
immediate environment (i.e., in relation to other surrounding
structures and tissues). These properties (collectively referred to
as "biomechanical properties") may include elasticity, shock
absorption, resilience, mechanical dampening, energy storage,
pliability, stiffness, rigidity, configuration, alignment,
deformation, mobility, and volume. In addition to these
biomechanical properties, biological tissues may have a complex
structure, which may include a plurality (two or more) of layers of
different types of sub-"tissues", which work in conjunction with
each other to moderate the function of the biological tissue.
Though biological tissue may have a complex structure, it is
generally considered a continuous medium.
[0035] The biomechanical properties of biological tissue may change
over time or in response to a variety of factors, including injury,
illness, repetitive movement (fatigue), and age. For example,
biological tissues may lose or gain flexibility or rigidity over
time, resulting in all adverse impact on tissue function. According
to embodiments of the present invention, biomechanical properties
of biological tissues may be altered by a plurality of excisions
(perforations) of biological tissue to remove a total pre-selected
volume of excised tissue. It is believed that the location of the
perforations in the biological tissue and the volume of tissue
removed in each perforation, and the sum of all perforations, is
particularly relevant to the impact such excisions have on the
integrity of the biological tissue (i.e., maintaining structural
integrity and function, amongst others) and the amount of change in
the biomechanical properties of the tissue. For example, in one
embodiment, the volume of the individual pores or perforations
removed may be such that the overall change in density is
proportional to the decrease in load stress, where load stress is
the biomechanical property being affected.
[0036] It is believed that the affect of perforating the biological
tissue influences biomechanical properties, such as structural
pliability, by creating areas of flexibility wherein the
perforations act as flexible "diaphragm pumps" which significantly
change the extensibility of tissues in critical anatomical areas of
significance thereby restoring biomechanical efficiencies of the
physiological structures/tissues/systems being released from the
impingement.
[0037] Stated another way, the excision of tissue according to the
present disclosure produces areas within the biological tissue
where previously homogenous tissue is altered to tissue having
areas of positive and negative stiffness. As noted above,
biological tissue has distinct properties and structural hierarchy
in its design, architecture and function. In addition, biological
tissue may occur in vivo in layers and planes, akin to an onion.
The matrix complex of the present invention changes the
architecture of the biological tissue by changing what was a
continuous medium into a heterogeneous tissue with areas of
perforation. The result is a change in mechanical structure,
behavior, and function.
[0038] As indicated above, the present invention discloses an
arrangement, and a method of determining the arrangement, of
perforations to form one (and preferably two or more) matrices and
the arrangement, and method of determining the arrangement, of
matrices within a matrix complex oriented on the biological tissue,
to achieve a change in at least one biomechanical property of the
biological tissue. Moreover, the present invention discloses a
method for selecting the number and size of perforations to achieve
a desired change in at least one biomechanical property of the
biological tissue.
[0039] Having provided a biological tissue, the method may include
evaluating the topography, biomechanical and fundamental properties
of the biological tissue layer by layer, as appropriate. As
discussed above, a biological tissue may have more than one layer,
like an onion. The term "fundamental properties" refers to original
structure, nature and composition. Evaluation of the topography
(i.e., the physical structure of the tissue layers, including
depth, surface area, and the like) and biomechanical and
fundamental properties of each layer of the biological tissue
provides data concerning the overall structure of the biological
tissue and is relevant to determining the disparate effect on the
sub-tissues that a perforation extending through multiple
sub-tissues may impart. Evaluation of the topography of the
biological tissue and its sub-tissues may be achieved by as
described herein. Evaluation of the biomechanical properties of the
biological tissue and its sub-tissues may be achieved by as
described herein. It will be understood that evaluating and
characterizing the biomechanical properties of the biological
tissue will include determining the physical constants and forces
operating in the tissue, including elastic constants and atomic
forces, which may vary between biological tissues and between
sub-tissues within a biological tissue.
[0040] The method further comprises orienting a matrix complex in
the biological tissue, where the matrix complex is comprised of
one, and preferably, more than one matrix of perforations. The
matrix complex may be oriented with respect to the biological
tissue so that the constituent matrices are substantially
"balanced" within the tissue. By "balanced" it is meant that the
matrices are position in such an orientation that the
region-specific effects on biomechanical properties in the areas in
and adjacent each matrix are balanced across the entire biological
tissue so as to achieve the desired change in the biomechanical
property of the biological tissue as a whole, without adversely
affecting the integrity, or other desirable structural
characteristics of the tissue. It is particularly desirable that
the balance results in a substantial equilibrium of forces in the
biological tissue under both static and dynamic conditions. It is
further desirable that the matrix complex is positioned with
respect to the biological tissue to reduce shearing effects between
the individual matrices in the matrix complex and between the
perforations within the matrix. This balancing may result in an
increase to the integrity of the biological tissue.
[0041] To this end, the matrices forming the matrix complex may be
positioned according to a mathematical relationship comprising a
mathematical algorithm. This mathematical relationship and the
associated algorithm will be described in further detail below. It
will be understood that the matrix complex may, in an alternate
embodiment, be unbalanced, though a balanced arrangement is
preferred.
[0042] Now the mathematical relationship of the matrices within the
matrix complex will be described. In one embodiment, the
mathematical relationship governing the positioning of the matrices
within the matrix complex is based on a mathematical algorithm. The
mathematical algorithm may use a factor of .PHI. (Phi) to create a
model of the biological tissue to find the most efficient placement
of the matrices to alter the biological property of the biological
tissue. For purposes of this application, the factor Phi is 1.618
and represents any fraction of a set of spanning vectors in a
lattice having the shortest length relative to all other vectors'
length. The factor Phi is believed to be particularly relevant to
the organizational structure and development of many biological
tissues, organs, and larger bodies, being a ratio that tends to
appear repeatedly in nature. In one embodiment, the algorithm may
use a factor of Phi, however, the algorithm may use a derivative of
Phi, such as, but not limited to, an addition of, a subtraction of,
a multiplication of, a division of, all exponent of, a root of, or
such other mathematical derivative of, Phi.
[0043] The mathematical algorithm may additionally or alternatively
include an atomic relationship factor, which may comprise a
predictable relationship between the volume removed in each
perforation and the change in the fundamental and biomechanical
property of the biological tissue. This is described briefly above.
In one embodiment, the relationship of the removed volume to the
magnitude of the change in the biomechanical property of the tissue
may be mutually exclusive.
[0044] The mathematical algorithm may include a non linear
hyperbolic relationship between planes of biological tissue and at
any boundary or partition of neighboring tissues, planes and spaces
in and outside of the matrices. However, the relationship may be
linear, nonlinear or Euclidean or non-Euclid space.
[0045] As previously discussed, each matrix comprises an array of
perforations in a pattern. The matrix may properly be depicted
mathematically as a point lattice, in which the perforations
comprise points in the lattice. It will be understood that each
matrix will comprise rows and columns of perforations, and that
each row will have a length and each column will have a length.
Within each matrix and between the perforations in a matrix, there
may be one or more mathematical relationships which govern the
positioning of the perforations with respect to each other, and
within the matrix. For example, according to one embodiment, the
row length and column length of the matrix may correlate to each
other by means of a linear algebraic relationship. The linear
algebraic relationship may be described as a vector relationship
following planar and Euclidian geometry. According to another
embodiment, each perforation in the matrix may have continuous
linear vector spaces with derivatives up to infinite number
relationship "n". Still further, given that each matrix has a
surface area calculable with reference to its row lengths and
column lengths and given that the matrix complex covers a total
surface area representing the sum of the matrix surface areas, each
perforation may have a proportional relationship to the matrix
complex surface area. Each perforation may further bear a linear
relationship with one, more than one, or all of the other
perforations in the matrix.
[0046] It will be understood that each matrix may be defined either
or both two-dimensionally and three-dimensionally. The
two-dimensional surface appearance of the matrix will be defined by
the openings of the plurality of perforations in the matrix. In one
embodiment, these openings may be arranged in a pattern such that
the matrix is tessellated. The tessellation may comprise a
repeating, or a non-repeating pattern, or a blend of both repeating
and non-repeating patterns. The tessellations may be one or a
combination of more than one of Euclidian, non-Euclidian, regular,
semi-regular, hyperbolic, parabolic, spherical, or elliptical
tessellations. Mathematics relating to each of these tessellations
is known. In one embodiment, the tessellation may be a square
having the property of being able to be subdivided into a
tessellation of equiangular polygons to a derivative of n. Due to
the linear relationship of the matrices, the constant of phi can be
used in biological tissue as a tissue architectural ruler in
creating a virtual 3D archetype which can correlate to a
mathematical algorithmic code which can be translated by computer
via a software program. According to another, related embodiment,
the tessellation may comprise an infinite number of tessellating
tetrahedrons within the square for desired tissue effect and
volumetric requirement. In other words, given the desired volume of
tissue that needs to be removed to achieve a given change in the
biological tissue, the number of individual perforations, which
define the boundaries of the tessellation, will be restricted
largely by the technological limitations in removing a volume of
tissue at the perforation. It will be understood that present
technology limits the feasibility of such an "infinite"
tessellation, but that the number of tessellations may be
finite.
[0047] The tessellation may be directly or indirectly related to
stress or shear strain atomic relationships within the biological
tissue. In addition or in the alternative, the tessellation may be
directly or indirectly related to stress or shear strain atomic
relationships between the biological tissue and its surrounding
tissues. The relationship may be defined with respect to a
mathematical array of position vectors between perforations.
According to another aspect of the invention, the method of the
present invention may include computing the mathematical array of
position vectors between perforations.
[0048] In light of the large number of mathematical calculations
governing the location of the matrix complex, the matrices, and the
perforations in the matrices, the methods of the present invention
further contemplate the provision a software program adapted to
calculate the location of the matrix complex on the biological
tissue and the location of the perforations within the matrices,
all using the mathematical algorithm and related to (accounting
for) the structural hierarchy of the biological tissue, which may
be determined by understanding the homogeneity of layers of the
biological tissue. The software program will preferably be adapted
to calculate the location of the perforations on the tissue
according to the algorithm and variables described above, including
the respective pore depth and size, to achieve orientation of the
matrix complex on the biological tissue having sufficient volume
excision to achieve the desired change in the biomechanical
property of the tissue.
[0049] In another embodiment, the software program may transmit the
location of the matrix complex and the perforations to a tissue
perforating device. And in still a further embodiment of the
invention, the software program may additionally transmit control
instructions to the tissue perforating device. The control
instructions refer to the instructions that guide the tissue
perforating device (laser) around the biological tissue and govern
the operation of the tissue perforating device.
[0050] In one specific embodiment of the method involving treatment
of the sclera, a predetermined pattern of perforations in critical
zones in the scleral tissue of the eye is believed to
proportionally decrease load stress/shear stress of the scleral
tissue of the eye globe which has become contracted due to aging or
some other process which interferes or disrupts the normal
biomechanical and physiological properties and processes of the
functions of the eye. The "micro expansion" in the critical areas
is small enough that it does not significantly change the overall
diameter or expansion of the entire globe of the eye. The
mathematical model for scleral decompression is based on age
related geometric and tissue characteristics. The scleral
decompression is accomplished by removing strategic areas of sclera
in opposing quadrants of the anterior globe segment whereby a
series of connective tissue partitions are created using a non
contact method and Er:YAG 2.94 um wavelength. The resulting "gap
junctions" can be created in a number of design patterns, however,
they will preferably have a critical width which is necessary to
prevent scleral residual tissue approximation thereby inhibiting
normal fibroblast activity retarding the connective tissue healing
cycle. Collagen reorganization is loosely organized and less
differentiated. It is believed that this strategic removal of
scleral tissue creates "flexible diaphragm pumps" that act as
extensible dividing membrane partitions allowing for decompression
of scleral load stress and restoration of biomechanical efficiency
in the tissues that interact in the internal and dynamic functions
of the eye including but not limited to: accommodative system (lens
function), hydrodynamic system (aqueous outflow), neuromuscular
system (afferent/efferent visual pathways), neurovascular system
(choroidal/retina functions). It is believed that the volume and
location of tissue ablation is relevant to achieving areas of
decreased load stress, decreased tissue strain and deformation, as
well as decompression of receptors necessary for maintaining the
homeostasis of the fluidic, dynamic, and chemical processes both
extracellular and intracellular. It is also thought that the
effects of the Er:Yag Laser wavelength and mechanism of action
produces slight desirable thermal and mechanical effects which
denature the collagen tissue fibers of the residual sclera and
retard or even inhibit the healing process. The newly created
"flexible diaphragm pumps" restore the normal biomechanical
efficiency of the underlying dynamic systems and allow a return of
function.
[0051] This method of treatment in this embodiment may entail
vaporizing a predetermined volume of scleral tissue either in the
anterior or posterior eye globe in critical zones. This method is
the vaporization of scleral tissue as calculated proportionally by
segmental zones of micro-cylinders or micro-prisms with specific
emphasis on decompression of scleral load stress in three critical
zones in the anterior globe. The described distances are radial
measurements from the visual axis: proximal zone is .gtoreq.0.5 mm
from the posterior surgical limbus and .ltoreq.0.8 mm central zone
is equidistant between proximal zone and distal zone distal zone is
just anterior to the annulus of inn or the insertion of the EOM
specifically: at least 5.0-5.5 mm from the posterior surgical
limbus.
[0052] In this embodiment (specific to removing sclera from the
anterior globe), the approximation of the inner wall edge of the
individual pore or perforation produced may be no less than 400 um
and ideally is greater than or equal to 600 um. This is to disrupt
the normal tissue healing response and to retard fibroblast
formation disallowing cross-bridging and thus maintaining the
maximum amount of evacuated tissue despite eventual tissue healing.
In another embodiment tissue adjacent the posterior globe may be
altered according to the methods of the present invention.
[0053] The minimum depth in scleral tissue should be calculated to
produce full thickness micropuncture to the subchoroidal lamina to
improve uveal-scleral aqueous flow to have an effective decrease
effect in IOP. If soft tissue layers are released microscopically
through the subchoroidal level, all immediate decrease in average
of 3-mmHg IOP should be achieved. This depth for the average
scleral thickness is approximately equal to or greater than 600 um.
This should be calculated as f(x) whereas x=scleral depth. Scleral
depth is regionally specific in the globe. The total spherical
volume removed per quadrant is calculated in relationship to the
tangential axis of the globe and as a function of scleral depth in
the specific globe zone location. Proportional volume will be
removed in perforations whereas the overall surface area should not
exceed the width of 5.0 mm and the length of 5.0-5.5 mm and depth.
The shape of the overall surface representation of the "dot matrix"
of perforations is variable and may exist in a variety of patterns,
including a "cross Pattern" or diamond pattern. This diamond
pattern can be further described as a series of tessellated
equilateral triangles or 3D tetrahedral series.
[0054] The biological tissue may have a range of isotropic elastic
constants across the medium. In such an embodiment, the matrices
have a position within the matrix complex, wherein the position of
the matrices is selected to create a non-monotonic force
deformation relationship in the biological tissue.
[0055] The embodiments have been described, hereinabove. It will be
apparent to those skilled in the art that the above methods and
apparatuses may incorporate changes and modifications without
departing from the general scope of this invention. It is intended
to include all such modifications and alterations in so far as they
come within the scope of the appended claims or the equivalents
thereof.
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